Biogen‘s stock soars after positive results from study of Alzheimer‘s treatment

Shares of Biogen Inc. soared 12% toward a five-month high in premarket trade Friday, after the biotechnology company and Tokyo-based Eisai Co. Ltd. announced positive results from a phase 2 trial of the companies‘ Alzheimer‘s treatment. The final analysis at 18 months of the 856-patient clinical study with BAN2401 in early Alzheimer‘s disease demonstrated statistically significant slowing in clinical decline and reduction of amyloid beta accumulated in the brain, the companies said in a release late Thursday. "New data provide compelling evidence to further support amyloid hypothesis as a therapeutic target for Alzheimer‘s disease," the companies said. Biogen‘s stock had lost 6.2% year to date through Thursday, while Eisai‘s U.S.-listed shares had run up 25% and the S&P 500 had gained 2.4%.